Stuck Definition and 836 Threads

Homework Statement y'' - 2y'+ 6y = 0 y(0) = 3 y(5) = 7 Find a solution y(t).Homework Equations The Attempt at a Solution I found the characteristic equation: x2 - 9x = 0, which has roots at 0 and 9. Therefore y(t) = C1e0x + C2e9x Using the initial conditions to solve this: 3 = C1 + C2 7 =...

Homework Statement If AB = BA and p is a nonnegative integer, show that (AB)^p = (A^p)(B^p) Homework Equations N/A The Attempt at a Solution I would love to attempt a solution, but I don't even know where to begin. I guess my first question is, how can I generalize matrices so...

Homework Statement In order for a jumbo jet to take off, it must reach a final velocity of 360 km/h. Given that it moves at a constant acceleration and that the runway is 1.8 km long, find the minimum initial acceleration required to reach the final velocity. The jet starts at rest...

Homework Statement Use Fourier transforms to get solution in terms of f(t) adn g(t)Homework Equations d4u + K2*d2u =0 dx4 (space) dt2 u(0,t)=f(t) u'(0,t)=g(t) u''(L,t)=0 u'''(L,t)=0 The Attempt at a Solution I been working no it for hours the best I got is k4U...

Hi, I'm almost at the end of a question but i seem to be stuck. I have the answer though.. so I am up to here so can someone please help me complete this: (\frac{n + \frac{1}{c}}{\frac{s}{n} }) [\mu^2 - 2\mu(\frac{n \overline{y}}{n+\frac{1}{c}})] then i completed the square: (\frac{n +...

So the question asks me to use the following information to graph the function f over the closed interval [-2, 5] i) The graph of f is made of closed line segments joined end to end. ii) The graph starts at the point (-2, 3) ii) The derivative of f is the step function in the figure shown...

Basically I am taking the lab concurrently with the class, unfortunately we learn how to do the lab a few weeks after we do it so its becoming quite depressing. I could probably slide out of it with a B or C and get absolutely nothing out of it. I should have waited to take it butI didnt realize...

The integral is t(4+9t)^(1/2) dt I have tried u-sub and integration by parts but i can't figure it out. u=4+9t du=9 Does not help because i still have that t to deal with. I have spent more time then i want to admit trying to figure it out, and there are plenty more in the hw...

A 25.0g ice cube at its melting point is added to a calorimeter water at 25.4ºC. When thermal equilibrium is reached, the final temperature of the mixture is at 15.0ºC. The original volume of water in the calorimeter was? This is all the data given. A. 93.4mL B. 136mL C. 209mL D. 228mL...

Homework Statement http://books.google.ca/books?id=iND9qjGHCFYC&pg=PA23&lpg=PA23&dq=calculate+the+molar+volume+of+methane+at+300K&source=bl&ots=nAtQSpwJGo&sig=lE8BtkzjGHC3-W2JC5ghtfANxrA&hl=en&ei=6Am5StfVKpbktQP6_NmxDg&sa=X&oi=book_result&ct=result&resnum=4#v=onepage&q=&f=false The question...

So i have the following question(s) in my homework assignment (This question is in regards to a car that is pushing a truck that has broken down in the middle of the road and i have to describe the motion/force): Wouldn't the answer be that the car is pushing with less force than the truck is...

I Have been using A Byte of Python, and I am now stuck on the Continue Statement. Here is my code. #!/usr/bin/python #Filename: continue1.py while True: s = input('Enter something : ') if s == 'quit': break if len(s) < 3: print('Too Small') continue print('Input is of...

Homework Statement Not sure how to approach this one, does anyone have an idea? BTW, in the top line it should read xz-plane, not xy.

I had the garage door cracked open slightly, so that's how he got in. I have now opened the door fully, but he can't seem to find his way out. He flies to the back of the garage, perches on a box as if he's preparing to make a run for it. But when he flies toward the exit, he perches on the...

Hi everyone, I am stuck on the problem below. I think it has something to do with Poisson Process?? I would really appreciate it if someone could point me in the right direction. An electronic switching device occasionally malfunctions and may need to be replaced. It is known that the...

Homework Statement A horizontal massless spring of spring constant k is attached to a immovable wall at one end and a mass of 0.45kg at the other end. The spring which was not originally under tension, is now extended by 0.18 m by pulling the mass horizontally. The mass was then released by...

This is turning out to be difficult for me, and I haven't even reached the part where he explains the theory of relativity itself :( "Let us suppose that the shot is fired from the guard's-van, and the echo comes from a screen on the engine. We will suppose the distance from the guard's-van...

Hi everyone. I'm stuck on a problem, banging of head etc. Basically, I've got a time-evolution problem restricted to the positive quadrant of complex space, where the state of the system \psi \in \mathbb{C} is described by the following type of ODE: \frac{{d\psi \left( t...

in plan view, the shoreline of a bay may be approximated by a curve f(x) = -x2 + 2x between one headland at x = 0 and another at x = 1km, where (f) is also measured in km. at low tide, the edge of the sea just reaches each headland, following a straight line between them. calculate in km2 the...

A solid steel shaft 10 m long and 70mm diameter is subjected to a torque of 4.5 kNm. In order to save the weight the solid shaft is to be replaced be a thin walled hollow shaft of wall thickness 10mm. What diameter of hollow shaft is required to carry the same torque if the maximum allowable...

I graduated with a B.S in Physics this passing May. I applied to many graduate schools for nanoscience, however only one accepted me "provisionally". My GPA was lower than a 3.0 (2.8). So, now I'm stuck with a B.S in Physics and I'm not going to graduate school (I can't afford it). I really...

A sky diver weighing 180 lb falls vertically downward from an altitude of 5000ft and opens the parachute after 10 s of free fall. assume that the force of air resistance is 0.75(v) when the parachute is closed and 12(v) when the parachute is open, where the velocity v is measured in ft/s. a)...

hello ! need to find the volume of V: { x^2+y^2=z , x^4+y^4=1 } i don't know how to set up the triple integral caue i didnt find any way to understand the surface projection on the xy plane . I would appreciate any help ...

an i section beam 5 meters long, supported both ends, with a 2nd moment of area 120x10 ^-6 m ^4 a depth of 250mm and a uniformaly distributed load of 20KN/m caculate, max bending moment min bending stress the radius of curvature of the beam where the bending moment is maxaimun (...

Homework Statement a neutral kaon at rest decays to pion- and pion+ , if kaon rest mass is 497.7MeV/c^2, and the pions rest mass is 139.6MeV/c^2, what are the kinetic energies of the resulting pions? Im very stuck with this, and not sure where to start, how can i find Ek of pions, if i don't...

Hey guys, Homework Statement I have an assignment, which is to Solve Schrodinger's equations, for a certain potential distribution, which can be divided up into three regions. A solution for one of the regions is of the form: Ae^{kx} If you substitute this into Schrodinger's...

Homework Statement When one calculates electric potentials, it involves integrating over the charge distribution, and for a surface with a uniform charge distribution, you encounter an integral of the form: \int_{\mathcal{S}} \frac{d^2x'}{|\vec{x}-\vec{x'}|} Where \vec{x} is the vector...

can someone please help me with this question. i don't know how to do this.

Homework Statement Equation: dy/dx=x+1/3y^2 where y>0 Homework Equations I'm to show that (1/2x^2+x+8)^1/3 is a solution The Attempt at a Solution Splitting it up in x/3y^2+1/3y^2 has been futile and I'm out of ideas. Can anyone help me see the light?

Homework Statement Prove the pigeonhole principle directly. so basically |Nk-{x}|=|Nk-1| if k>1 is an integer and x belongs to the set of naturals. Homework Equations The Attempt at a Solution I have no idea even where to begin.

State Gauss' Law A spherical volume carries a uniform charge density \rho_0. A particle of mass m and charge -q is placed inside the sphere at radial distance r. (This additional charge does not distort the field arising from the \rho_0 charge density.) Show that the particle oscillates...

1. The distance between two slits is 0.0500 nm and the distance to the screen is 2.50 m. What is the spacing between the central bright fringe and the first-order fringe? Use yellow light with a wavelength of 580.0 nm. Answers: a. 0.010m b. 0.029m c. 0.290m d. 0.10m e. 0.6m 2. y =LtanΘ...

Homework Statement a robotic space probe of mass 7600 KG is traveling through space at 120 m/s. Mission control determines that a change in course of 30.0 degrees is necessary and instructs the probe to fire rockets perpendicular to its direction of motion. If the escaping gas leaves the...

Homework Statement I need help with question number 8 and 9. I have no idea where to start. Homework Equations The Attempt at a Solution

You're stuck on a crossword clue or something and the answer is on the tip of your tongue but you just can't get it out?What do you do? I find it helps to walk slowly up and down with a slight rocking motion and with the hands held tightly behind the back whilst mumbling like an idiot. Try it...

I accidently got into AM radio mode in my car for the last two days, and I can't figure out how to take it back into FM because there isn't a stupid AM/FM button. I had to have hit some funky combination of buttons to go into AM and now I am stuck. ANYWAYS, I've been stuck with this AM radio for...

Homework Statement Define specific heat capacity and latent heat of fusion. Copper melts at a temperature of 1356 K with a latent heat of fusion of 210,000 J/kg (Joules per kilogram). Calculate the thermal energy required to convert a copper bar with a mass of 40 kg at a temperature of...

stuck on light intensity problem... 1. Homework Statement http://s685.photobucket.com/albums/vv212/dewdr0p714/?action=view&current=physicsexam2q5withoutphotocell.jpg A conducting rod slides down 2 frictionless copper tracks at a constant velocity. There is a .50 T magnetic field...

Homework Statement Prove that the area of an ellipse with equation \frac{x^2}{a^2} + \frac{y^2}{b^2} = 1 is A=\pi ab. Homework Equations The Attempt at a Solution I solved for y, set up the integral for area with lower limit -a and upper limit a, did u substitution...

Homework Statement Integrate -9e^x - 28 / e^2x + 9e^x + 14 It gives a hint which is substitute u = e^x. Homework Equations The Attempt at a Solution I want to integrate by partial fractions if possible... however before I can do that, I need to make the substitution, and I...

Kirchoff's Rule...problem stuck! Homework Statement http://img5.imageshack.us/img5/5307/physishelp.jpg The Picture Explain above explains it all, I have attached a same file if you might need it! It is the same picture. Homework Equations V=IR Thats all I know! The Attempt at a Solution...

Homework Statement Hey guys. So I've got half a ball from 0 to point A as you can see in the pic and I need to calculate the potential of the ball at point A. So what I did is to break it into disks. I found the differential potential of a volume ring which is inside the disk at point A...

Hi, first post here. I've been trying (out of personal interest, not homework) to re-derive http://www.springerlink.com/content/mm61h49j78656107/" relatively famous calculation on the ground state of Helium from 1929. And I'm stuck at one point. What Hylleraas did, was to parametricize the...

please help with this construction question I am really stuck! question is:- a reinforced concrete beam is to be 700mm deep. the minimum width of beam is to be used and 20mm size aggregate has been specified. three 25mm diameter bars have been calculated for tension reinforcement and three 16mm...

Hi, I am torn between these two majors that I will absolutely love. Here are the basics: CS: I think that I would enjoy programming (although at this point, all I really know is a little java), and I like solving puzzles. However, I think that CS might be a little too theoretical for me...

Homework Statement Integrate (sin5x)(cos4x)dx Homework Equations The Attempt at a Solution I tried substituting u as (sin5x), but wound up with something way more complicated than what I started with. Same thing happens if I substitute cos^4 for u. I have no idea what to try...

Hi, I am also having trouble with the hockey puck question. A hockey puck rebounds from a board as shown in my diagram. The puck is in contact with the board for 2.5 ms. Determine avg acceleration of the puck over the interval. Vi = 26 m/s Vf = 21 m/s I tried the cosine law but I keep...

Can you help me solve this equation? Its the Gompert equation, dp/dt=cln(K/p)p. I used substution to get -ln(u) = ct+b, where c is a constant, and bi s a constant of integration. Next we have -ln(ln(k/p)) evaluated from pt to po = ct+b Then ln(k/p) from pt to po = Bexp(-ct). This is...

Homework Statement You are trying to loosen a stuck bolt on your RV using a big wrench that is 50 cm long. If you hang from the wrench, and your mass is 55 kg, what is the maximum torque you can exert on the bolt? Homework Equations T=Fr I did T=55kg*.5m The Attempt at a...

The question: A grasshopper makes four jumps. The displacement vectors are (1) 27.0 cm due west (2) 23.0 cm, 35.0^{o} due south of west (3) 28.0 cm, 55.0^{o} south of east and (4) 35.0 cm, 63.0 ^{o} north of east. Find the magnitude and direction of the resultant displacement. Express the...